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(svn r21378) -Codechange: move the logic for reading bytes from a savegame into a class

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pull/155/head
rubidium 14 years ago
parent e589dca253
commit 1fb2849566
1 changed files with 61 additions and 46 deletions
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107
src/saveload/saveload.cpp
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@ -273,6 +273,48 @@ struct LoadFilter {
virtual size_t Read(byte *buf, size_t len) = 0;
};
/** A buffer for reading (and buffering) savegame data. */
struct ReadBuffer {
byte buf[MEMORY_CHUNK_SIZE]; ///< Buffer we're going to read from.
byte *bufp; ///< Location we're at reading the buffer.
byte *bufe; ///< End of the buffer we can read from.
LoadFilter *reader; ///< The filter used to actually read.
size_t read; ///< The amount of read bytes so far from the filter.
/**
* Initialise our variables.
* @param reader The filter to actually read data.
*/
ReadBuffer(LoadFilter *reader) : bufp(NULL), bufe(NULL), reader(reader), read(0)
{
}
FORCEINLINE byte ReadByte()
{
if (this->bufp == this->bufe) {
size_t len = this->reader->Read(this->buf, lengthof(this->buf));
if (len == 0) SlErrorCorrupt("Unexpected end of chunk");
this->read += len;
this->bufp = this->buf;
this->bufe = this->buf + len;
}
return *this->bufp++;
}
/**
* Get the size of the memory dump made so far.
* @return The size.
*/
size_t GetSize() const
{
return this->read - (this->bufe - this->bufp);
}
};
/**
* Instantiator for a load filter.
* @param chain The next filter in this chain.
@ -379,7 +421,7 @@ struct MemoryDumper {
* Get the size of the memory dump made so far.
* @return The size.
*/
size_t GetSize()
size_t GetSize() const
{
return this->blocks.Length() * MEMORY_CHUNK_SIZE - (this->bufe - this->buf);
}
@ -395,17 +437,11 @@ struct SaveLoadParams {
size_t obj_len; ///< the length of the current object we are busy with
int array_index, last_array_index; ///< in the case of an array, the current and last positions
size_t offs_base; ///< the offset in number of bytes since we started writing data (eg uncompressed savegame size)
MemoryDumper *dumper; ///< Memory dumper to write the savegame to.
SaveFilter *sf; ///< Filter to write the savegame to.
LoadFilter *lf; ///< Filter to read the savegame from.
/* When saving/loading savegames, they are always saved to a temporary memory-place
* to be flushed to file (save) or to final place (load) when full. */
byte *bufp, *bufe; ///< bufp(ointer) gives the current position in the buffer bufe(nd) gives the end of the buffer
byte buf[MEMORY_CHUNK_SIZE]; ///< memory for reading savegame data
ReadBuffer *reader; ///< Savegame reading buffer.
LoadFilter *lf; ///< Filter to read the savegame from.
StringID error_str; ///< the translatable error message to show
char *extra_msg; ///< the error message
@ -577,37 +613,14 @@ void ProcessAsyncSaveFinish()
}
/**
* Fill the input buffer by reading from the file with the given reader
*/
static void SlReadFill()
{
size_t len = _sl.lf->Read(_sl.buf, sizeof(_sl.buf));
if (len == 0) SlErrorCorrupt("Unexpected end of chunk");
_sl.bufp = _sl.buf;
_sl.bufe = _sl.buf + len;
_sl.offs_base += len;
}
static inline size_t SlGetOffs()
{
return _sl.offs_base - (_sl.bufe - _sl.bufp);
}
/**
* Read in a single byte from file. If the temporary buffer is full,
* flush it to its final destination
* @return return the read byte from file
* Wrapper for reading a byte from the buffer.
* @return The read byte.
*/
static inline byte SlReadByteInternal()
byte SlReadByte()
{
if (_sl.bufp == _sl.bufe) SlReadFill();
return *_sl.bufp++;
return _sl.reader->ReadByte();
}
/** Wrapper for SlReadByteInternal */
byte SlReadByte() {return SlReadByteInternal();}
/**
* Wrapper for writing a byte to the dumper.
* @param b The byte to write.
@ -818,7 +831,7 @@ int SlIterateArray()
/* After reading in the whole array inside the loop
* we must have read in all the data, so we must be at end of current block. */
if (_next_offs != 0 && SlGetOffs() != _next_offs) SlErrorCorrupt("Invalid chunk size");
if (_next_offs != 0 && _sl.reader->GetSize() != _next_offs) SlErrorCorrupt("Invalid chunk size");
while (true) {
uint length = SlReadArrayLength();
@ -828,7 +841,7 @@ int SlIterateArray()
}
_sl.obj_len = --length;
_next_offs = SlGetOffs() + length;
_next_offs = _sl.reader->GetSize() + length;
switch (_sl.block_mode) {
case CH_SPARSE_ARRAY: index = (int)SlReadSparseIndex(); break;
@ -848,7 +861,7 @@ int SlIterateArray()
void SlSkipArray()
{
while (SlIterateArray() != -1) {
SlSkipBytes(_next_offs - SlGetOffs());
SlSkipBytes(_next_offs - _sl.reader->GetSize());
}
}
@ -908,7 +921,7 @@ static void SlCopyBytes(void *ptr, size_t length)
switch (_sl.action) {
case SLA_LOAD_CHECK:
case SLA_LOAD:
for (; length != 0; length--) *p++ = SlReadByteInternal();
for (; length != 0; length--) *p++ = SlReadByte();
break;
case SLA_SAVE:
for (; length != 0; length--) SlWriteByte(*p++);
@ -1601,9 +1614,9 @@ static void SlLoadChunk(const ChunkHandler *ch)
len = (SlReadByte() << 16) | ((m >> 4) << 24);
len += SlReadUint16();
_sl.obj_len = len;
endoffs = SlGetOffs() + len;
endoffs = _sl.reader->GetSize() + len;
ch->load_proc();
if (SlGetOffs() != endoffs) SlErrorCorrupt("Invalid chunk size");
if (_sl.reader->GetSize() != endoffs) SlErrorCorrupt("Invalid chunk size");
} else {
SlErrorCorrupt("Invalid chunk type");
}
@ -1647,13 +1660,13 @@ static void SlLoadCheckChunk(const ChunkHandler *ch)
len = (SlReadByte() << 16) | ((m >> 4) << 24);
len += SlReadUint16();
_sl.obj_len = len;
endoffs = SlGetOffs() + len;
endoffs = _sl.reader->GetSize() + len;
if (ch->load_check_proc) {
ch->load_check_proc();
} else {
SlSkipBytes(len);
}
if (SlGetOffs() != endoffs) SlErrorCorrupt("Invalid chunk size");
if (_sl.reader->GetSize() != endoffs) SlErrorCorrupt("Invalid chunk size");
} else {
SlErrorCorrupt("Invalid chunk type");
}
@ -2348,6 +2361,9 @@ static inline void ClearSaveLoadState()
delete _sl.sf;
_sl.sf = NULL;
delete _sl.reader;
_sl.reader = NULL;
delete _sl.lf;
_sl.lf = NULL;
}
@ -2505,8 +2521,6 @@ SaveOrLoadResult SaveOrLoad(const char *filename, int mode, Subdirectory sb, boo
/* Mark SL_LOAD_CHECK as supported for this savegame. */
if (mode == SL_LOAD_CHECK) _load_check_data.checkable = true;
_sl.bufe = _sl.bufp = NULL;
_sl.offs_base = 0;
switch (mode) {
case SL_LOAD_CHECK: _sl.action = SLA_LOAD_CHECK; break;
case SL_LOAD: _sl.action = SLA_LOAD; break;
@ -2609,6 +2623,7 @@ SaveOrLoadResult SaveOrLoad(const char *filename, int mode, Subdirectory sb, boo
}
_sl.lf = fmt->init_load(_sl.lf);
_sl.reader = new ReadBuffer(_sl.lf);
if (mode != SL_LOAD_CHECK) {
_engine_mngr.ResetToDefaultMapping();

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